On Sun, Apr 04, 2021 at 04:13:17PM +0300, Mark Bloch wrote:
> On 4/4/21 1:33 PM, Leon Romanovsky wrote:
> > On Fri, Apr 02, 2021 at 02:47:23PM +0300, Dan Carpenter wrote:
> >> The nla_len() is less than or equal to 16. If it's less than 16 then
> >> end of the "gid" buffer is uninitialized.
> >>
> >> Fixes: ae43f8286730 ("IB/core: Add IP to GID netlink offload")
> >> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> >> ---
> >> I just spotted this in review. I think it's a bug but I'm not 100%.
> >
> > I tend to agree with you, that it is a bug.
> >
> > LS_NLA_TYPE_DGID is declared as NLA_BINARY which doesn't complain if
> > data is less than declared ".len". However, the fix needs to be in
> > ib_nl_is_good_ip_resp(), it shouldn't return "true" if length not equal
> > to 16.
>
> What about just updating the policy? The bellow diff should work I believe.
I didn't know about ".validation_type", but yes this change will be enough.
>
> diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
> index 0abce004a959..65e3e7df8a4b 100644
> --- a/drivers/infiniband/core/addr.c
> +++ b/drivers/infiniband/core/addr.c
> @@ -76,7 +76,9 @@ static struct workqueue_struct *addr_wq;
>
> static const struct nla_policy ib_nl_addr_policy[LS_NLA_TYPE_MAX] = {
> [LS_NLA_TYPE_DGID] = {.type = NLA_BINARY,
> - .len = sizeof(struct rdma_nla_ls_gid)},
> + .len = sizeof(struct rdma_nla_ls_gid),
> + .validation_type = NLA_VALIDATE_MIN,
> + .min = sizeof(struct rdma_nla_ls_gid)},
> };
>
> static inline bool ib_nl_is_good_ip_resp(const struct nlmsghdr *nlh)
>
> >
> > Thanks
> >
>
> Mark
